A liquid crystal display device is configured to include a liquid crystal display panel which displays images and a backlight unit which illuminates the liquid crystal display panel from a back surface side of the liquid crystal display panel.
Hereinafter, a case where the liquid crystal display panel is arranged in the vertical orientation will be described.
In the related art, an edge-light type backlight unit is disclosed (refer to International Publication Pamphlet No. 2012/002074). In the edge-light type backlight unit, a rectangular light guide plate is arranged through an optical sheet group at the back surface side of the liquid crystal display panel, a light-reflecting sheet is arranged at the back surface side of the light guide plate, and a light source unit is arranged to face the lower end surface of the light guide plate.
Light emitted from the light source unit passes through the lower end surface of the light guide plate to enter to an inside of the light guide plate. The light entering to the inside of the light guide plate is emitted from the front surface of the light guide plate. The light emitted from the front surface of the light guide plate is diffused and condensed by the optical sheet group to enter to an inside of the liquid crystal display panel.
When the backlight unit evenly illuminates the liquid crystal display panel, a display area of the liquid crystal display panel becomes evenly bright.
The light guide plate is supported between a frame-shaped panel chassis (hereinafter, referred to as a P chassis) arranged at the front surface side of the light guide plate and a dish-shaped backlight chassis (hereinafter, referred to as a BL chassis) arranged at the back surface side of the light guide plate.
Notch-shaped recesses are provided to the peripheral portion of the light guide plate. Protrusions are provided to the BL chassis. By engagement of the recesses of the light guide plate with the protrusions of the BL chassis, the light guide plate is positioned.
With respect to the protrusions engaged with the recesses of the light guide plate, since the protrusions block light, there is a problem in that brightness of the vicinity of the protrusions is decreased.
In the backlight unit disclosed in International Publication Pamphlet No. 2012/002074, the protrusions are covered by erecting a part of the light-reflecting sheet, so that the light shielding caused by the protrusions is suppressed.